1. Field of the Invention
The present invention relates to lasers and, more particularly, to a laser system and a method for permitting the laser to be switched on and off substantially instantaneously.
2. The Prior Art
In many industrial and commercial applications of lasers, particularly Argon ion type lasers, it is required that the laser beam be available on a selective basis at different times during system operation. This requirement has been accommodated in the prior art by leaving the laser beam on all the time (i.e., whenever the system is operating) and selectively utilizing the beam by means of optical gating. This has the disadvantage of requiring frequent replacement of the laser. More specifically, an Argon ion type laser typically has a limited plasma current lifetime. Thus, for systems which operate continuously, the laser plasma current lifetime limits the system operational life expectancy.
It would be more desirable and efficient to merely switch the laser beam on and off as dictated by system demands, while leaving the laser filament on. However, while a laser will readily extinguish the instant laser beam current is interrupted, ignition is not so simple. Once the laser beam current is interrupted there is a considerable delay required to re-ignite the laser beam. For example, Argon ion type laser ignition requires storage of a considerable amount of electrical energy and accumulation of sufficient ignition energy results in an undesirable delay which cannot be tolerated for many applications.